mule skin vs. cowhide for heads

[Snake]

I've been reading the merrits of both of these materials for replacement heads for congas. It seems that the head is the most important contributor to the overall sound of the drum with respect to the drum components and not considering the player.

With this as a base statement, if I were to buy a medium grade conga and then in time replace the heads once my playing improved, would I get better tone from mule skin heads or cow hide heads like what Timba equips on their premium congas?

I have read Jonny Conga's opinion that he would go with mule skins, but I have also read from other expert players here that the Timba congas sound the best and it's because of their cow hide heads?

Finally, whichever type of head is choosen, do the thicknesses match up even between the 2 or will mule skin heads be thinner or thicker than comprable cow hide heads?

Thanks for reading my posts and putting up with a barrage of questions from a clueless newbie.